Vacuum interrupters are used with, for example, medium voltage switchgears. DE 10 2008 031 473 discloses a vacuum interrupter which has metal part sections and a ceramic section. In order to enhance a dielectric behaviour, the vacuum interrupter has rings of isolating material in regions of transition from a metal part to a ceramic part. This insulating ring material has additional additives inside the insulating material, such as metal oxides, in order to influence the insulating properties.
This construction is not efficient in, for example, series arranged multiple vacuum interrupters.